Module 4 - DNA, genes and chromosomes

Question 1

What is a gene?

Answer 1

A gene is a section of a DNA sequence that codes for a polypeptide chain or functional RNA

Question 2

What is an allele?

Answer 2

An allele is a different version of the gene from the same polypeptide

Question 3

How is DNA different in Eukaryotes compared to prokaryotes?

Answer 3

In Eukaryotes it is long, linear and wound around histone proteins. In prokaryotes it is short, circular ad not wound to histone proteins

Question 4

What organelles have their own DNA? how is it similar to prokaryotes?

Answer 4

Chloroplasts and mitochondria. They are both short and circular and are not associated with histone proteins

Question 5

What is a triplet of DNA bases in a sequence called?

Answer 5

Codon

Question 6

What is a genome and proteome?

Answer 6

Genome is the compete set of all genes in a cell. Proteome is the full range of proteins that a cell is able to produce

Question 7

What are introns and exons?

Answer 7

Introns don’t code for amino acids to make polypeptides. Exons are the areas that do code to make amino acids.

Question 8

What are multiple repeats?

Answer 8

This is when DNA sequences are repeated over and over again in a gene.

Question 9

What is the locus?

Answer 9

A fixed position on every chromosome where a specific allele will always be.

Question 10

What is a homologous pair? Example

Answer 10

This is a pair where both chromosomes contain the same genes but can have different alleles. Two 1 chromosomes will form a homologous pair.

Question 11

What is meant by non-overlapping?

Answer 11

This means that in each triplet, the next triplet cannot contain a DNA base from the previous triplet.

Question 12

What is meant by amino acids being degenerate?

Answer 12

This is when one or more codons can code for one amino acid

Question 13

How many possible triplets are there?

Answer 13

64